Dynamic Insole

ABSTRACT

A dynamic insole that flexes and returns as the plantar fascia flex and return, comprising a medial first windlass-shaped front cutout for great toe phalanges and a lateral second diagonal-shaped front cutout for fourth and fifth toe phalanges, further comprising medial and lateral upwardly-curved side walls wherein a medial side wall comprises a lobe, and made from a first material having a hardness value between 40 Shore A and 90 Shore A.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not applicable.

STATEMENTS REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT

Not applicable.

BACKGROUND

The embodiments of the present invention satisfy the needs of having adynamic insole that discourages pronation, of allowing plantar bands tolengthen and shorten as a wearer walks, provides arch support, reducesmetatarsal head pressure, distributes overall loads, and supports thenavicular bone.

Information relevant to attempts to address these problems can be foundin U.S. Pat. Nos. 6,453,578; 6,604,301; 6,871,422; 6,976,322; 7,010,869;7,707,751; 7,827,703; 7,832,119; 8,453,346; 8,667,716; 8,800,168; andU.S. Patent Application 2009/0172972; which are not admitted to be priorart with respect to the present invention by its mention in thisBackground Section. However, it is desirable to have a better apparatusthan is disclosed in the references.

U.S. Pat. No. 7,832,119 claims a first metatarsal head lift, but itneither discloses nor claims a lift for the other metatarsal heads nor acutout for phalanges. The insole in the present invention extends tojust behind (anterior to, closer to the ankle than to the toe)metatarsal heads I through V.

U.S. Pat. No. 8,667,716 claims a metatarsal insert slot for inserting awedge under all five metatarsal heads. In the present invention, thegreat toe cutout allows the metatarsal pad or engagement surface to bethinner or lower than can be accomplished with a wedge, which canincrease wearer comfort.

Podiatrists frequently treat patients for damaged plantar fasica. Fasciais a tissue, like tendons, that connects directly to the bone. Fascianeed stress and release, but under constant stress fascia can becomeirritated. Stress is caused not by the duration of standing, but by howa person stands, e.g., with repetitive movements to the right thatoverextend due to poor posture such that the right foot supinates underthe load and the left foot pronates under the load and the left archcollapses and the left plantar fascia overextends. Thus at a basic levelwhat is needed is a dynamic insole that helps fascia stress and release.

When a person walks, they land on their heels and roll forward towardsthe toes. At the heel landing, muscle memory pulls the toes back suchthat all five digital slips of the plantar fascia are extended andtight. As the foot rolls towards the mid-step, the foot is in asupinating position. The three small toes (toes III-V) and theirrespective plantar fascia then relax, in the order V-IV-III. At mid-toe,the foot starts moving towards a pronating position. At the end of thestep, when all five toes are on the ground and the heel is off theground, if there is poor arch support then all plantar fascia remaintight and are extended due to the arch's fallen position. Thus what isspecifically needed is a dynamic insole that anatomically appropriatelyflexes and releases when a wearer is walking, running or shifting loadson the foot; and that flexes and returns as the plantar fascia flex andreturn, while supporting the arch.

The present invention supports the arch by means of a medial archsupport and by means of toe cutouts that allow the metatarsal heads tosink into the insole, such that the arch curvature is increased and theplantar fascia release and relax. The toe cutouts allow the metatarsalheads to fall, and as they fall the curvature of the arch is able toincrease. As the metatarsal heads fall, the insole deflects downwardsand then spring back to the first undeflected position. The insole isable to deflect or flex downwards, and then return, because it is madeof a material having a hardness that allows insole acts as a flexiblespringboard. This flexing and returning enables an even greater releaseand return of planta fascia than otherwise.

The embodiments of the present invention are made to flex and releasewith the movement of the foot. The elements of the invention that makeit dynamic are primarily the toe cutouts and the material hardness. Theinsole comprises a windlass-shaped front cutout at the great toe, and adiagonal-shaped front cutout at the fourth and fifth toes. The insolefurther comprises a material having a durometer hardness value ofbetween 40 and 90 Shore A, such that the insole deflects under theapplication of weight but then returns or springs back to its originalposition. This durometer is at least approximately 20 units higher thanthe typical factory-supplied insole of 20 Shore A. The higher durometeralso enables the sidewalls to remain upwardly-curved. The insolethicknesses also taper down into the insole edges, which renders theinsole more flexible than otherwise. The toe cutouts are shaped to bringthe insole distal tip up to points that are just proximal and anteriorto the metatarsal heads; these termination points ensure that themetatarsal heads can fall under the weight of the foot. The frontwindlass cutouts that extend into the upwardly-curved sidewalls aremade, by means of their tapered thickness and their 40 to 90 Shore Amaterial, to fall under a wearer's weight and then to spring back tosupport the return of the toes. Toe cutouts, rather than material orwedges to raise metatarsal heads, are used because the more the toesfall, the more the toe relaxes; and the more the toe relaxes, the morethe plantar fascia releases and relaxes. This compression and return atthe metatarsal heads, in combination with the cutouts, allow the plantarfascia to flex and release and support the return. In other words, thefront of the insole acts as a diving board or springboard.

The embodiments of the present invention discourage pronation througharch support. The insole's arch section side wall is built with a sidelobe that comprises sufficient excess material to prevent it fromcollapsing under the weight of a user. In combination with the flex andrelease of the insole due to the durometer, this lobe helps the arch popback up when the foot releases from a flex. The lobe-supported archingalso benefits the plantar fascia, because the higher the arch, the morethe planta fascia relax, because a higher arch shortens the distancebetween where plantar fascia connect to the calcaneus and to the secondphalange of each toe.

The side lobe also encourages the foot to cushion itself. The lobeextends from the mid-foot medial wall and it makes the insole wider thancould fit without bending or compressing into average-sized shoes. Whenthe insole is forced into a shoe, this overwide wall compresses to fitinto the shoe. The wall in turn compresses the fatty tissue of the soleof the foot, which act as an extra cushion and by volume support thearch. This mid-foot insole element supports the foot as it tightens themuscle structure, ligaments and tendons in the metatarsal area as youprepare to push into the next step.

The embodiments of the present invention prevent the need tooversupinate. Elite runners strike the foot on the toe; more precisely,on the metatarsals of the fifth toe. Many of these runners oversupinatewhen their arch is insufficiently supported.

SUMMARY

The embodiments of the present invention are directed to an insole thatsatisfies the needs set out in the Background section.

The embodiments of the present invention comprise a dynamic insolecomprising an insole proximal end to be worn adjacent a wearer's leg, aninsole distal end, an insole lower surface and insole thicknesses, andinsole edges where the form-fitted insole upper surface and the insolelower surface meet, wherein the insole further comprises:

a form-fitted insole upper surface that is fitted to contours of awearer's foot;

a first material having a hardness between 40 Shore A and 90 Shore Awhich enables the insole under a weight of a wearer's foot to deflectdownwards from an original position and then return back to the originalposition;

insole thicknesses tapering down into the insole edges;

a medial arch support;

a deep heel cup;

a flat heel portion in the insole lower surface;

a medial upwardly-curved side wall and a lateral upwardly-curved sidewall for cradling a foot;

a lobe for widening the insole, wherein the lobe extends from the medialupwardly-curved side wall;

a first windlass-shaped cutout at the insole distal end that revealsmetatarsal heads I and II;

a second diagonal-shaped cutout for fourth and fifth toe phalanges thatreveals metatarsal heads III, IV and V; and an insole distal end tonguebetween and formed by the first and second cutouts, the insole distalend tongue comprising a flat lower surface.

Optionally, the first material is dual-density ethylene-vinyl acetatefoam.

Optionally, the first material has a Shore hardness value of 45.

Some Advantages of the Embodiments of the Invention

For any toe, the plantar band is shortened when the metatarsal head isallowed to drop and the arch is supported. Shortening the plantar bandreduces strain to the plantar fascia. Shortening the plantar band alsoencourages supination as this facilitates arch support.

The deep heel cup distributes weight over a large area, which preventsthe heel from rolling inward with pronation, which helps support inwardand outward movement of the calcaneus as well as encourages asvaris/valgus position when calcaneus is rested. In addition the deepheel cup creates a border which contains the soft tissue on the bottomof the heel in a prescribed area. The soft tissue comprises a cushion.

The form-fitted attribute maximizes insole contact with the bottom ofthe foot. This disperses and distributes energy, preventing pressureareas that lead to open blisters, ulcerations, loss of dermis, breakdownof fatty tissues used to cushion the foot, bruised metatarsals andunnatural foot placement. It also stops the fatty tissues from spreadingand flattening out; flattening out would decrease their efficacy.

A material with a Shore durometer between 45-65 is compressible. Amaterial with a Shore durometer between 75-90 is rigid and hassubstantial memory, e.g., if deflected downwards it remains flexeddownwards. Shoe insoles are generally 10-20 durometers and they quicklylose their shape.

The insole medial side wall comprises a lobe at the medial arch. When awearer inserts a foot into a shoe containing the insole, the foot isbedded on the medial side wall creating a downward pressure. Theinterior of the medial side of the shoe acts as a form that restrictsthe medial side of the insert, in particular the lobe, from spreadingout and or flattening. Thus the medial side wall of the insert stayshigh and its arch support stays in place. This arrangement also has theeffect of discouraging foot pronation, which is very important becausesupination is the natural and healthy foot method. The foot shouldstrike when walking or running minus the small percentage of thepopulation that may have a foot deformity.

These and other advantages will become apparent as the embodiments ofthe invention are used.

DRAWINGS

These and other features, aspects and advantages of the embodiments ofthe method will become better understood with reference to the followingdescription, appended claim and accompanying drawings where:

FIG. 1 shows a top plan view of an embodiment of the invention, leftfoot insole;

FIG. 2 shows a bottom plan view of an embodiment of the invention, leftfoot insole;

FIG. 3 shows a front elevation view of an embodiment of the invention,left foot insole;

FIG. 4 shows a rear elevation view of an embodiment of the invention,left foot insole;

FIG. 5 shows a right side elevation view of an embodiment of theinvention, left foot insole;

FIG. 6 shows a left side elevation view of an embodiment of theinvention, left foot insole;

FIG. 7 shows a perspective view of an embodiment of the invention fromthe top, left foot insole; and

FIG. 8 shows how the insole flexes or deflects downwards from a firstposition and then returns back to the first position.

REFERENCE NUMERALS FOR DRAWINGS

-   dynamic insole 10-   insole lower surface 15-   insole upper surface 20-   medial arch support 25-   deep heel cup 30-   medial upwardly-curved side walls 35-   lateral upwardly-curved side walls 40-   lobe 45-   flat heel portion 50-   insole proximal end 55-   insole distal end 60-   first windlass-shaped front cutout for great toe phalanges 65-   second diagonal-shaped front cutout for fourth and fifth toe    phalanges 70-   insole distal end tongue 75-   insole distal end tongue flat lower surface 80

DESCRIPTION Definitions

A form-fitting insole is an insole that tightly s the contours of thebottom and sides of the foot.

The toes are, from medial to lateral:

The first toe, also known as the hallux (“big toe” or “great toe”), theinnermost toe;

The second toe, or “long toe”;

The third toe, or “middle toe”;

The fourth toe, or “ring toe”;

The fifth toe, “little toe”, “pinky toe”, or “baby toe”, the outermosttoe.

The metatarsal bone can be divided into three parts; base, body andhead. The base is the part closest to the ankle and the head is closestto the toe. The narrowed part in the middle is referred to as the bodyof the bone.

Metatarsal head I corresponds to the great toe and metatarsal head Vcorresponds to the little toe.

The American Society for Testing and Materials (ASTM) D2240 standardrecognizes twelve different durometer scales. These scales are referredto as durometer types. A durometer type is specifically designed todetermine a specific scale, and the scale does not exist separately fromthe durometer. The A scale is for softer plastics, while the D scale isfor harder ones. However, the ASTM D2240-00 testing standard calls for atotal of 12 scales, depending on the intended use; types A, B, C, D, DO,E, M, O, OO, OOO, OOO-S, and R. Each scale results in a value between 0and 100, with higher values indicating a harder material. Thus ahardness value of 40 on the A scale is referred to as 40 Shore A.

Ethylene-vinyl acetate (EVA) is a co-polymer of ethylene (C₂H₄) andvinyl acetate (CH₃CO₂CHCH₂). EVA foam is almost as soft and flexible asmany rubbers, but is easier to process and manipulate in manufacturingof different goods due to its thermoplastic properties.

DESCRIPTION OF THE PREFERRED EMBODIMENT AND BEST MODE

As shown in the figures, the preferred embodiment and best mode of thepresent invention comprise a dynamic insole 10 comprising an insoleproximal end 55 to be worn adjacent a wearer's leg, an insole distal end60, an insole upper surface 20, an insole lower surface 15 and insolethicknesses, and insole edges where the form-fitted insole upper surface20 and the insole lower surface 15 meet, wherein the insole furthercomprises:

a form-fitted insole upper surface 20 that is fitted to contours of awearer's foot;

a first material having a hardness between 40 Shore A and 90 Shore Awhich enables the insole under a weight of a wearer's foot to deflectdownwards from an original position and then return back to the originalposition;

insole thicknesses tapering down into the insole edges;

a medial arch support 25;

a deep heel cup 30;

a flat heel portion 50 in the insole lower surface 15;

a medial upwardly-curved side wall 35 and a lateral upwardly-curved sidewall 40 for cradling a foot;

a lobe 45 for widening the insole, wherein the lobe 45 extends from themedial upwardly-curved side wall 35;

a first windlass-shaped cutout 65 at the insole distal end that revealsmetatarsal heads I and II;

a second diagonal-shaped cutout 70 for fourth and fifth toe phalangesthat reveals metatarsal heads III, IV and V; and

an insole distal end tongue 75 between and formed by the first andsecond cutouts, the insole distal end tongue comprising a flat lowersurface 80.

Preferably, the first material is dual-density ethylene-vinyl acetatefoam.

Preferably, the first material has a Shore hardness value of 45.

An insole having a Shore hardness value of 85-90 has the longest life.An insole having a Shore hardness value of 45 provides more cushion thanhigher values (46-90) but it breaks down faster.

The preferred material is foam EVA. Gel in contrast keeps its thicknessbut when it wears out it becomes less dense because the moleculesdisperse.

Some advantages of the embodiments of the apparatus were previouslyenumerated in the Summary section. Every advantageous feature does notneed to be incorporated into every embodiment of the apparatus and/ormethods.

Although these versions of the invention have been described inconsiderable detail, other versions are possible. For example,embodiments can comprise combinations of the features described herein,such as combinations of the dependent claims. Therefore, the spirit andscope of the appended claims should not be limited to the description ofthe versions contained therein.

I claim:
 1. A dynamic insole comprising an insole proximal end to beworn adjacent a wearer's leg, an insole distal end, an insole uppersurface, an insole lower surface and insole thicknesses, and insoleedges where the form-fitted insole upper surface and the insole lowersurface meet, wherein the insole further comprises: a form-fitted insoleupper surface that is fitted to contours of a wearer's foot; a firstmaterial having a hardness between 40 Shore A and 90 Shore A whichenables the insole under a weight of a wearer's foot to deflectdownwards from an original position and then return back to the originalposition; insole thicknesses tapering down into the insole edges; amedial arch support; a deep heel cup; a flat heel portion in the insolelower surface; a medial upwardly-curved side wall and a lateralupwardly-curved side wall for cradling a foot; a lobe for widening theinsole, wherein the lobe extends from the medial upwardly-curved sidewall; a first windlass-shaped cutout at the insole distal end thatreveals metatarsal heads I and II; a second diagonal-shaped cutout forfourth and fifth toe phalanges that reveals metatarsal heads III, IV andV; and an insole distal end tongue between and formed by the first andsecond cutouts, the insole distal end tongue comprising a flat lowersurface.
 2. The insole of claim 1, wherein the first material isdual-density ethylene-vinyl acetate foam.
 3. The insole of claim 1,wherein the first material has a hardness value of 45 Shore A.